Existing psychological testing techniques include memory tests, fluid intelligence tests, intelligence quotient tests and chronometric based tests. Some said tests are available on-line at web sites.
However, existing techniques have a number of shortcomings. These include the fact that verbal instructions must be used in demonstrating the test to a test subject, such verbal instructions being presented to the subject in printed or oral form. The subjects must then translate the words into a state-dependent set of expectations about the type of stimulus-response requirements that will be encountered in the test. The translation process, however, is dependent upon the individual subject's language skills in the language of the instructions, and that subject's experience in using language to govern his or her behaviour.
Further, instructions provided in this manner, either by the interpretation of written instructions or by the verbal instruction provided by a supervisor conducting the test (as well as subsequent interactions between that supervisor and the test subject), can lead, almost inevitably, to the inadvertent altering of the test environment. This effect may be due to variations in the level of understanding by the subject, or instruction or subsequent interaction provided by the supervisor, who may conclude that more or less instruction, for example, is required for a particular subject. In some contexts this flexibility may be of value, but small changes in the test conditions can mask poor performance or, alternatively, can impair normal performance.
Other existing techniques are culturally dependent: at the simplest level, the use of verbal or written instructions as discussed above can impact on testing, because different instructions must be provided according to the language of the subject, thereby introducing variation dependent on the skill exercised in translating the instructions, and because some languages may be better adapted than others to expressing the necessary instructions. Most existing techniques employ tests that have a small number of forms, so that subjects repeating the test may soon re-encounter a test, or may deduce the nature of the variation between tests and benefit accordingly.
It is an object of the present invention to provide a psychological testing method and apparatus that avoids one or more of the above shortcomings.